1. Field of the Invention
This invention relates to a locking device used in combination with a power operated door opener.
2. Description of the Prior Art
The power operated door opener has been used substantially in residential areas in the last few years. The basic drive, either chain or screw, has become more reliable and the motor, gearing, clutches and switches have improved to the point that a failure is rare. In addition, a high rate of production has allowed a lower price whereby many homeowners can afford to install such openers, especially on overhead, horizontally pivoted garage doors. This type of garage door, which is called a "California" door, is used mainly in the Western part of the United States where there is seldom snow and ice to hinder the opening of the garage door.
The "California" door is usually made of wood and it is usually fitted to a two (2) car garage although a one (1) car garage can easily use this type of door. The shear size of this door, even if made from light weight wood such as pine makes the door quite heavy and therefore a balancing spring with the attending mechanism is used to allow a person to lift and close the door. Still, it is inconvenient in inclement weather to get out of the car, open the garage door and get back in the car to drive the car into the garage. In addition, most garage doors require the closing by hand from the outside which is also inconvenient in inclement weather. The power operated garage door opener with a radio control device activated inside the car also provides security whereby a person can open the garage door, drive into the garage and close the garage door behind without unlocking the car doors. All of these factors stated above have created a tremendous market for power operated garage door openers.
However, along with the increased usage of power operated garage door openers, there has been an increase in garage burglaries as two (2) strong men can break the garage door opener mechanism since favorable leverage is provided by the horizontally pivoted garage hinges. The breaking of the mechanism allows the door to be opened and the garage burglarized.
There are no known, self locking, devices for power operated garage door openers, however, there are latch mechanisms on doors, gates and the like which are discussed below.
U.S. Pat. No. 3,259,413 to Steckle describes a door latch with a pivoted cam locking plate. This reference directs itself to a cleanout door on a soaking pit associated with slab mills in the steel industry. The device is activated by a rope which disengages the latching dog allowing the heavy door to fall free and some other means (not shown) is used to close the door which allows the latching dog to catch the lip of the door and hold the door in a closed position. This reference is different in that the latch does not rely on the power of the opening door mechanism to release the latch dog as in the present invention but instead relies on a rope pulled by some outside force.
Another reference is U.S. Pat. No. 1,324,428 to Mair. Mair describes a latch which contains a gravity operated latching dog used primarily for gates. A lever is required to be lifted which lifts the latching dog out of the way of the striker and therefore allows the gate to be opened. Again, the reference clearly does not read on the present invention as the present invention uses the power operated door opener to urge the latching dog to lock the door and to disengage the latching dog to open the door.
Smith in U.S. Pat. No. 2,579,621 describes a latch for an overhead horizontally pivoted door to latch the door in the up position to keep the door from falling to the closed position and injuring someone. Therefore this is a safety latch and locks the door in the open position until some force pulls on a release rope allowing the door to close. This invention is not used in combination with a power operated door opener and further requires pulling on a rope to release the latch which is not required by the present invention.
Piras in U.S. Pat. No. 3,161,426 describes a latch for use on automobiles such as the one used for the automobile hood. The latch is released by pulling on a cable located in the dashboard of the automobile. This invention does not teach a device that is self latching and self releasing and used in combination with a power operated door opener.
Other references of interest are U.S. Pat. No. 2,526,979 to Tomlinson, U.S. Pat. No. 4,174,128 to Styck and U.S. Pat. No. 3,453,014 to Johnson.
The novel features which are believed to be characteristics of the invention, both as to its organization and its method of operation, together with further objects and advantages thereof, will be better understood from the following description in connection with the accompanying drawings in which a presently preferred embodiment of the invention is illustrated by way of example. It is expressly understood, however, that the drawings are for purposes of illustration and description only, and are not intended as a definition of the limits of the invention.